Natural variability

Hill says natural climate variability is probably the cause of Leeuwin current moving further than usual.

The currents are also influenced by both decadal and annual variation.

"It's a case of trying to tease apart all those variations and see what might be causing what."

Ignoring seasonal variability, Hill says the EAC is getting stronger with climate change, while the Leeuwin Current is weaking.

"Australia had a wetter year than usual this year, but that doesn't mean we're not still on a drying climate trend," she says. "You get similar variations in the ocean from year to year."

But the warmer waters are not welcomed by all.

Rodney Treloggen, Chief Executive of the Tasmanian Rock Lobster Association based in St Helens, says fishers are concerned at what he describes as a "bad year" for the industry in the south-east and east coast.

"We know the warmer waters have an impact, but we're not sure how much," he says.